Drafting machine



H. WVIEDEMADNN April 25', 1944.

' DRAFTING MACHINE Filed May '7, 1941 s Sheets-Sheet 1 ATTORAZ'YS'Apri125,1944.

H. WIE DEMANN DRAF'I'ING MACHINE Filed May 7. 1941 3 Sheets-Sheet 2 ATTOHNE'YS Filed May '7, 1941 3 Sheets-Sheet-S A TTORAE'YS Patented Apr.25, 1944 DRAFTING MACHINE Hans Wiedemann, West New York, N. J., assignorto Keuffel & Esser Company, Hoboken, N. J., a corporation of New JerseyApplication May 7, 1941, Serial No. 392,239

15 Claims.

This invention relates generally to parallel motion drafting devices ofthe kind in which the several tools which the draftsman handles mostfrequently are embodied, in principle, in one unit to obviate thenecessity of a draftsman reaching about for a required tool and therebyenabling the draftsman to keep his attention concentrated directly uponthe drawing.

Drafting devices of this character are common in which adjacent ends oftwo arms are pivoted together, the free end of one arm being anchored tothe remote side of a drafting board while the free end of the other armis provided with a head comprising a protractor and straight-edges whichare in fixed angular relation and move about the center of theprotractor as an axis. Such straight-edges have heretofore been soassociated with the protractor as to be set and locked at any angle ofthe protractor or to be automatically locked at predetermined intervals.However, the instrumentalities effecting the setting of thestraightedges with respect to readings on the protractor have beencharacterized by difficulty in the manual actuation of the lockingdevice because of its inaccessibility.

One object of the present invention is a drafting device of thecharacter described, wherein the locking devices for the straight-edgesare readily accessible for manipulation without moving the hand from theactuating knob on the protractor head.

The invention also has for one of its objects locking and stop mechanismfor the straightedges which may conveniently be actuated by either thethumb or a finger, as found most convenient, of the hand manipulatingthe knob to move the straight-edges to the desired relative position. Incarrying this aspect of the invention into efiect, a rotatable wheel ispreferably provided on the knob, which is movable in either direction tounlatch the straight-edges and permit them to be moved freely to anyangular position but which, on release, will effect looking of thestraight-edges at the nearest even predetermined position.

Another object of the invention is to return the rotatable wheel on theknob to initial position whenever it is released by the operator.Accordingly, power is stored in power storing devices when the wheel ismoved from initial posi tion which is utilized to return the wheel.

The invention further seeks an instrumentality transferring the rotarymovement of the thumb or finger actuated devices to the Iatchat H).

ing devices for the protractor with a minimum number of parts to simpifyassembly and to avoid the necessity of interlocking lever arms and othermovement transferring devices.

The invention also resides in the details of construction by which thedrafting device is made practical from the standpoint of ease andconvenience in manufacture and durability and facility in use.

These and other objects of the invention and the means for theirattainment will be more apparent from the following detaileddescription, taken in connection with the accompanying drawingsillustrating one embodiment by which the invention may be realized, andin which:

Figure l is a perspective View showing the drafting machine of thisinvention mounted on a drawing table;

Figure 2 is a view showing the head of the drafting device of thisinvention in vertical section;

Figure 3 is a view of the drafting head in vertical section taken in theplane perpendicular to the plane of the section illustrated in Figure 2and on the line 3--3 of Figure 2, looking in the direction of thearrows;

Figure 4 is a fragmentary view in outside elevation of the specificinstrumentalities by which the rotary movement of the manually actuateddevice is changed to a movement of translation;

Figure 5 is a plan view taken in the planes indicated by the line 5-5 ofFigure 2, looking in the direction of the arrows, parts being removed toshow details of construction; and

Figure 6 is a detail View showing in elevation, the knob carrying frameof this invention. 7

Referring first to Figure 1, there is illustrated a typical endless bandand pulley type of drafting machine which comprises a pair of arms 6, 1each comprised of tubes 8 within which an endless band 9 in each armtravels. The adjacent ends of the arms are pivoted together, as The freeend of one arm is anchored, as at 12, to the side of a drafting boardWhile the free end of the other arm is provided with a supporting headl4 comprising the knob or handle l6, 2. protractor l8 and frame means 20supporting the straight-edges 22. Obviously the arms may assume anyconvenient structural shape.

As shown, the tubes 8 of arm I extend into and are retained in a framemember 24 of the head, which frame member comprises an outer flange 26within which the pulley 28 turns. Inwardly of flange 26 is a cylindricalflange 39 concentric with the axis of the head. Rotatably mounted withinthe cylindrical flange 36, as by the ball recess 32, 33 and ballbearings 34, is a cylindrical hub portion 35 which is integral with thepulley 28 and retains the bearing member 33 by means of a retaining ring36 threaded to the upper end of the hub 35. Thus the pulley 28 is freeto rotate within the arm portion 26 of the head without friction.

The pulley member 28 is rabbeted as at 38 to receive the protractorplate I8 and a locking plate 40 spaced from the protractorplate by aspacing ring 42 whereby the locking plate 46 and the protraotor I8 arefixed, in spaced relation, to the pulley by means of the screw or othersecuring means 45. Within the hub 35 of the pulley is disposed a sleeve44 functioning as a pivot pin and having its upper end of reduceddiameter, as indicated at 46, so that a shoulder 48 is providedsubstantially fiush with the upper surface of the pulley hub 35.The'sleeve 44 is secured to, as by being made integral with, aplate-like bottom portion 50 to which the straight-edge supporting frame20 is secured as by the screws The knob I6 is secured to the pivot pin44 so that rotation of the knob I6 will rotate the straight-edgesupporting frame 20 whenever that frame is released from the pulley bydisengaging a common type of latch member 54 from the toothed latchingplate 40, as will be understood. The knob I6 is operatively connectedwith the pivot pin in the following manner: The knob I6 is recessed, asat 56, and receives a generally cylindrical or cup-shaped knob supporting frame member comprised of the cylindrical or annular wall 60 anda bottom wall 62 which extends beyond the circumferential margin of thewall 60 as at 6| to support a manually actuatable device controlling thelatch 54 as hereinafter described. The knob I6 is secured to the Wall 60as by a screw 64 while the bottom wall 62 is keyed, as at 66, to thepivot pin 44. A nut 65 is threaded on to the reduced portion 46 of pivotpin 44 to seat the bottom wall 62 of the knob frame 60-62 against spacinring 63 on shoulder 48. Rotary movement of the knob I6 and hence of theframe member 6062 will turn the sleeve-like pivot pin 44 (within hub 35)and with it the straight-edge supporting frame 20.

The manually actuatable devices controlling the latch are carried by theknob above the level of the arm and in a position to be operated by thesame hand of an operator as is used to grasp the knob. Rotatable withinthe cup-shaped member 6062 is a cup-shaped female member ,5

68 having in its bottom an axial aperture II! within which extends acylindrical thrust member portion I4 of the nut 65 which is threaded onthe end of the pivot sleeve 44. Female member 68v is positioned by aflange 13. The thrust member portion 14 receives one end of the coilspring 16 which bears against the bottom of an actuated inverted malemember 18 also within the female member 68. The male member I8 has aperipheral flange 79 at its uppermost portion by which it is guided bythe Wall 63 of the knob frame. The male member 18 is positioned againstrotation with respect to the knob frame 6ll62 by means of a lug or key82 disposed in a longitudinal slot 84 formed in the wall 66 of the knobframe.

The actuated male member 78 is provided with an axial bore 86 withinwhich is fixed, asby the set screw 88, an axially disposed plunger 90disposed in the bore of the pivot member 44 and having, at its lowerend, a cylindrical head 92 within an enlarged portion 93 of the bore ofthe pivot member 44. The head 92 is conveniently formed with anangularly related or bevelled surface 95 serving as a cam.

The latch 54, Figure 5, which is pivoted at its one end, as at 55, isconnected to a slide 94 which reciprocates in a radially extending slot96 formed in the straight-edge supporting frame 20. This slide extendstoward the axis of the head to a point where it can be engaged by a ball98 movable in an axially extending recess formed by a cut-away portionI66 in the integral flange 56, the straight-edge supporting plate 20 anda cut-away portion I!!! in a supplemental plate I62 secured to thestraight-edge supporting frame 29 by means of the screws 5|. Thus whenthe plunger 93 is pressed downwardly, it displaces the ball 98 to theright, as viewed in Figure l, and moves the slide 94 in a direction torelease the latch 54 from a recess 4! in the latching plate 46. Theplunger 30 is reciprocated in the following manner: The upper edge ofthe female cupshaped member 68 is formed with a slot I04 branching intwo arms I03, I35 in opposite directions in a generally downwarddirection. Slot mouth I64 normally receives a pin I66 secured to theouter surface I5 of the actuatable member 78 and which pin moves ineither branch slot depending on the direction of rotation of the femaleactuator 68. Preferably there are two such pins and associated slotsdiametrically opposite one another.

Carried between the outwardly extending flange portion 6! of the member60-62 and the knob I 6 is an annular rotatable member III) which may belikened to a star wheel and is provided with spaced substantiallyradially extending finger grips or fins III. This member is looselyrotatable on the member 6062 but is constrained to a limited arcuatedisplacement with respect thereto by means of a finger II2 positioned ina groove II3 in the hub of the annulus H0 and secured thereto as by ascrew Finger H2 passes through a slot portion N6 of extended arcuatewidth in the wall 66 of the knob supporting frame 6Il62 which is shownas opening into the slot 84 therein. The finger also extends into alongitudinal slot II! in the female member 68. Thus when the controlmember H6 is rotated, the finger H2 moves the female member '68 throughthe same angle to reciprocate the plunger 96.

The cooperating latching member is shown in greater detail in Figure 5as an angularly shaped lever 54 formed with the detent 53 at its one endwhich is shaped as to enter into and position it self in one of thelatching recesses 4| formed in the latching plate 40. The otherextremity of the arm 54 is formed with an aperture for reception on apin mounted on the straight-edge supporting frame. The lever 54 isnormally urged toward the latching plate at by the engagement, in a slotin the slide 64, of a pin H8 carried by a lever I26 pivoted as at I22,to the frame member 26. The free end of this lever is urged toward theaxis of the head, as by a spring I24, whereby the normal tendency of thelever is to move the slide 94 inwardly to draw the detent 53 intoengagement with the latching disc 46.

In order to hold the straight-edge at points intermediate theregistering position of the notches, a locking member I26 is providedwhich, since it is rarely used, is, carried in the illustratedembodiment at a low point, as on the frame 20. Any

convenient clamping lever or looking member may be provided within thepurview of this invention and no further discussion thereof is deemednecessary.

The operation of the device is apparent from the foregoing description.Sufilce it to say that a. draftsman may release the straight-edges byrotating the star wheel Hi] by the thumb or finger of the same handwhich engages the knob and without removing the hand from the knob.Rotation of annulus H0 in either direction rotates the female member 68and brings the upper and outer wall of one of the slots 103 or I05(depending upon the direction of rotation of the star wheel) intoengagement with the pin Hi5. This wall serves as camming means whichurges the pin I06 downwardly, bringing with it the male member 18.Member 18 being secured to the plunger 99, it depresses the plunger andcauses the cam face 95 to displace the ball 98 radially to move theslide 96 in a direction to move the latch to disengaged position. Uponrelease of the annulus I ill and thereby the release of the spring 16,the spring forces the male member 18 upwardly carrying with it thereciprocating plunger 4 90. The resultant upward movement of the pin I06 causes the female member 68 and the annulus H0 to turn and resumetheir normal positions. When the plunger is raised, the spring I24 movesthe slide 94 inwardly, thereby restoring the ball to its position ofrest substantially at the axis of the head and permitting the latch 54to be reengaged with the latching plate 40.

Various modifications will occur to those skilled in the art in thecomposition, configuration and disposition of the component elementsgoing to make up the invention as a whole as Well as in the selectionand combination of features to accomplish the results sought, and nolimitation is intended by the phraseology of the foregoing descriptionor illustrations in the accompanying drawings, except as indicated inthe appended claims,

What is claimed is:

1. In a drafting machine, in combination, a

supporting head adapted for free translatory movement over a draftingboard comprising first latching means, straight-edge supporting means,means for maintaining said latching means relatively fixed inorientation, pivot means rotatably supporting said straight-edgesupporting means, a second latching means, means mounting one of saidlatching means for movement into and out of engagement with the otherlatching means,

power storing means normally urging said movably mounted latching meansinto engagement with the other latching means, plunger means axiallyreciprocable with respect to said straightedge supporting means, cammeans on said plunger, manually actuatable coacting cam means to engageand depress the first named cam means for axially reciprocating saidplunger and means for moving one of said latching means between releasedand engaged positions with respect to the other latching means inresponse to reciprocatory axial movement of said plunger.

2. In a drafting machine, in combination, a supporting head adapted forfree translatory movement over a drafting board comprising latchingmeans, straight-edge supporting means, means for maintaining saidlatching means relatively fixed in orientation, pivot means rotatablysupporting said straight-edge supporting means, coacting latching means,means mounting one of said latching means for movement into and out ofengagement with the other latching means, power storing means normallyurging said movably mounted latching means into engagement with theother latching means, plunger means reciprocable with respect to saidstraight-edge supporting means, a pin on said plunger, a cylindricalmember rotatably carried by the head and formed with an arcuate slotwhereof the respective ends are in a lower plane than the intermediateportion and receiving the pin for reciprocating said plunger when saidmember is turned and. means for moving said movable latching meansbetween released and engaged positions in response to reciprocatorymovement of said plunger.

3. In a drafting machine, in combination, a supporting head adapted forfree translatory movement over a drafting board comprising latchingmeans, straight-edge supporting means, means for maintaining saidlatching means relatively fixed in orientation, pivot means rotatablysupporting said straight-edge supporting means, a knob on the pivotmeans, coacting latching means, means mounting one of said latchingmeans for movement into and out of engagement with the other latchingmeans, power storing means normally urging said movably mounted latchingmeans into engagement with the other latching means, rotatable controlmeans carried by the knob, plunger means movable with respect to saidstraight-edge supporting means and knob and extending therebetween, amale member carried by the plunger, a cylindrical coacting female memberactuated by the control means, pi and slot connections between the twomembers for reciprocating said plunger, said female member beingrotatable on said knob and means urging said members in oppositedirections.

4. In a drafting machine, in combination, a supporting head adapted forfree translator-y movement over a drafting board comprising latchingmeans, straight-edge supporting means, means for maintaining saidlatching means relatively fixed in orientation, pivot means rotatablysupporting said straight-edge supporting means, a knob on the pivotmeans, coacting latching means, means mounting one of said latchingmeans for movement into and out of engagement with the other latchingmeans, power storing means normally urging said movably mounted latchingmeans into engagement with the other latching means, plunger meanssupporting for reciprocatory movement relative to said straightedgesupporting means and relative to said knob, a cam on the lower end ofsaid plunger, a slide secured to said movable latching means having anend adjacent said plunger, a ball interposed between the cam surface onthe plunger and the said end of the slide, a rotatable member carried bythe head, operative connection between the rotatable member and theplunger to recip rocate the same whereby rotation of said rotatablemember is translated into sliding movement of the slide by the same handof the opa knob on the pivot means, coacting latching means, meansmounting one of said latching means for movement into and out ofengagement with the other latching means, power storing means normallyurging said movably mounted latching means into engagement with theother latching means, plunger means supported for reciprocatory movementrelative to said knob and relative to said straight-edge supportingmeans, means carried by said knob for moving said plunger meanscomprising telescoping cam means in operative relation to said plunger,an annulus rotatably mounted on the knob in a position to be moved bythe same hand of an operator as is used to grasp said knob, and ball andcam means coupling said movable latching means to said plunger formoving said movable latching means out of engagement with said otherlatching means in response to movement of said plunger.

6. In a drafting machine, in combination, a supporting head adapted forfree translatory movement over a drafting board comprising latchingmeans, straight-edge supporting means, means for maintaining saidlatching means relatively fixed in orientation, pivot means rotatablysupporting said straight-edge supporting means, a knob coupled to thepivot means, coacting latching means, means mounting one of saidlatching means for movement into and out of engagement with the otherlatching means, power storing means normally urging said movably mountedlatching means into engagement with the other latching means, plungermeans supporting for reciprocatory axial movement relative to said knoband relative to said straightedge supporting means, means carried by thepivot means and rotatable in a plane transverse to the axis thereof anddisposed adjacent said knob in a position to be moved at any point onits periphery by the same hand of an operator as is used to grasp saidknob and coupled to reciprocate said plunger axially, and means couplingsaid movable latching means to said plunger for moving said latchingmeans out of engagement with said other latching means in response toaxial movement of said plunger.

7. In a drafting machine, in combination, a supporting head adapted forfree translatory movement over a drafting board comprising latchingmeans, straight-edge supporting means, means for maintaining saidlatching means relatively fixed in orientation, pivot means rotatablysupporting said straight-edge supporting means, a knob on the pivotmeans, coacting latching means, means mounting one of said latchingmeans for movement into and out of engagement with the other latchingmeans, power storing means normally urging said movably mounted latchingmeans into engagement with the other latching means, plunger meanssupported for reciprocatory movement relative to said knob and relativeto said straight-edge supporting means, an annular groove in said knob,an annulus operatively connected to said plunger and rotatable in saidgroove for manually moving said plunger, and means coupling said movablelatching means to said plunger for moving said movable latching meansout of engagement in response to movement of said plunger.

8. In a drafting machine, in combination, a supporting head adapted forfree translatory movement over a drafting board comprising latchingmeans relatively fixed in orientation, straight-edge supporting meanspivotally supported for manual rotation relative thereto by a knobcoupled to said straight-edge supporting means and disposed thereaboveand having a device for securing said straight-edge supporting meansagainst pivotal movement comprising a pawl mounted on said straight-edgesupporting means for movement between a position engaging said latchingmeans and a position disengaged therefrom, a pawl control devicecomprising plunger means supported for reciprocatory movement relativeto the axis of said tool, an annular member in a position to be moved bythe same hand of an operator as is used to grasp said knob, meansactuating said plunger to move said pawl between said engaged and saiddisengaged positions comprising male and female members, the male memberof which is secured to the plunger and the female member of which isactuated by the annular member, power storing means tending to separatesaid members, at least one pin carried by one of said members, saidother member being formed with at least one cam groove engageable by apin to cam the male member downwardly upon rotation of the pin in eitherdirection, a slide connected to the pawl, coacting cam means carried bythe plunger and the slide to move said pawl to disengaged position.

9. In a drafting machine, in combination, a supporting head adapted forfree translatory movement over a drafting board comprising a latchingplate, straight-edge supporting means, means for maintaining saidlatching plate relatively fixed in orientation, tubular pivot meansrotatably supporting said straight-edge supporting means, a pawl, meansmounting the pawl for movement into and out of engagement with thelatching plate, power storing means normally moving the pawl intoengagement with the latching plate, a cup-shaped frame member secured tothe pivot means and formed with a peripheral flange, a knob secured tothe wall of the cupshaped frame member in spaced relation to the flange,the wall of said frame member being formed with a longitudinallyextending slot terminating proximate the flange in a peripherallyextending slot, an annular control member rotatably supported on theflange, a finger carried thereby and extending through the last namedslot in the frame member, a thrust member carried by the pivot meanswithin the cup-shaped frame member, a plunger within the tubular pivotmeans and extending thereabove, a male member carried on the upper endof the plunger having a peripheral flange slidably guided in thecupshaped frame member and formed with a lug reciprocable in the firstnamed slot therein, power storing means between the thrust member andthe male member, a female member within the first named frame member andformed with a longitudinally extending slot receiving the finger on theannular control member, diametrically disposed pin and slot connectionsbetween the male and female members to depress the plunger, a cam on thelower end of the plunger, a slide operatively connected with the pawland a ball between the cam and slide to move the slide to disengage thepawl from the latching plate when the plunger is in depressed position.

10. In a drafting machine, in combination, a supporting head adapted forfree translatory movement over a drafting board comprising latchingmeans relatively fixed in orientation, straight-edge supporting means,tubular pivot means supported for manual rotation and coupled to saidstraight-edge supporting means and disposed thereabove and having adevice for securing said straight-edge supporting means against pivotalmovement comprising a pawl mounted on said straight-edge supportingmeans for movement between a position engaging said. latching means anda position disengaged therefrom, a pawl control device comprisingaxially movable plunger means supported for reciprocatcry movementaxially within said tubular pivot means, means coupling said plunger tomove said pawl between said engaged and said disengaged positions, aknob on the pivot means, power storing means tending to engage said pawland means to actuate the plunger positioned adjacent the knob to bemoved by the same hand of an operator as is used to grasp said knob.

11. In a drafting machine, a member fixed in orientation, astraight-edge supporting frame, means for latching said frame to saidmember, a pivot pin having a generally tubular portion extending throughsaid member mounting said frame for rotary movement below said member, aknob fixed to said pivot pin above said member, a rod axiallyreciprocable within the generally tubular portion of said pivot pin,means adjacent the knob to axially reciprocate said rod, a cam surfaceat the lower end of said rod, and means below said member moved by thecam surface at the lower end of said rod engaging and actuating saidlatching means.

12. In a drafting machine, a member fixed in orientation, atstraight-edge supporting frame, means for latching said frame to, saidmember, a pivot pin having a generally tubular portion extending throughsaid member mounting said frame for rotary movement below said member, aknob fixed to said pivot pin above said member, a rod reciprocablewithin the generally tubular portion of said pivot pin, means adjacentthe knob to reciprocate said rod, a cam surface at the lower end of saidrod, a ball adapted to be engaged by said cam surface, and means belowsaid member moved by said ball under the influence of said rod foractuating said latching means.

13. In a drafting machine, a member fixed in orientation, 9,straight-edge supporting frame, means for latching said frame to saidmember,

erally tubular portion of said pivot pin, rotary means adjacent saidknob, means responsive to rotation of said rotary means for axiallyreciproeating said rod, and means below said member engaged by said rodand engaging and actuating said latching means in response to axialreciprocation of said rod.

1%. In a drafting machine, a member fixed in orientation, astraight-edge supporting frame, means for latching said frame to saidmember, a pivot pin having a generally tubular portion extending throughsaid member mounting said frame for rotary movement below said member, aknob fixed to said pivot pin above said member, a rod axiallyreciprocable within the generally tubular portion of said pivot pin,rotary means adjacent said knob and rotatable in either direction,operative connections between said rotary means and said rod andresponsive to rotation of said rotary means in either direction toreciprocate said rod axially, and means below said member for actuatingsaid latching means in response to axial reciprocation of said rod,

15. In a drafting machine, a member fixed in orientation, astraight-edge supporting frame, means for latching said frame to saidmember, a pivot pin having a generally tubular portion extending throughsaid member mounting said frame for rotary movement below said member, aknob'fixed to said pivot pin above said member, a rod reciprocablewithin the generally tubular portion of said pivot pin, rotary meansadjacent said knob, two concentric tubular elements, one element fixedto said rod, the second element connected to said rotary means and cammeans between said elements to cause axial reciprocation of said oneelement and said rod upon rotation of said second element, and meansbelow said member for actuating said latching means in response toreciprocation of said rod.

HANS WIEDEMANN.

CERTIFICATE OF COl'iRECTION.

Patent No. 2,5h7,625. April 55, 191m.

HANS WIEDEIIANN.

' It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 2,first column, line 5, for the word "recess" read--races-; and that thesaid Letters Patent should be read with this correction therein that thesame 'may conform to the record of the case in the Patent Office.

Signed and sealed this 8th day of August, A. D. 19%.

Leslie Frazer (Seal) Acting Commissioner of Patents.

